No Swimming

Blue Fire Crater with fumaroles, Kawah Ijen volcano, Java  (credit: Wikicommons)

There is nothing more relaxing after a long hike than swimming in a cool, mountain lake. It rejuvenates the body and spirit. However, some lakes are as toxic as battery acid. According to NASA, a lake inside of Blue Fire Crater in Java's Kawah Ijen volcano and not a place for swimming:

"has a pH of less than 0.3 on a scale of 0 to 14 with 7 being neutral. Lemon juice has a pH of 2 and battery acid has a pH of 1, by comparison".

A Landsat 8 photograph captured the turquoise blue of the acid lake that comes from dissolved chemicals in the water, including hydrochloric and sulfuric acids. Pure sulfur is mined at the crater's shore where steaming sulfuric vents (fumaroles) erupt from the still active volcano. Blue Fire lake is definitely not a place for a relaxing swim. WHB

Rare Plants Have Secrets The World's Navel